Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Photochemical smog causes cracking of rubber.
Reason (R): Presence of ozone, nitric oxide, acrolein, formaldehyde and peroxyacetyl nitrate in photochemical smog makes it oxidizing.
Choose the most appropriate answer from the options given below:
Assertion (A): Photochemical smog causes cracking of rubber.
Reason (R): Presence of ozone, nitric oxide, acrolein, formaldehyde and peroxyacetyl nitrate in photochemical smog makes it oxidizing.
Choose the most appropriate answer from the options given below:
- (A)(A) is false but (R) is true.
- (B)Both (A) and (R) are true but (R) is the true explanation of (A).✓ Correct
- (C)(A) is true but (R) is false.
- (D)Both (A) and (R) are true and (R) is not the true explanation of (A).
Answer: (B)
Solution
Photochemical smog is rich in ozone, peroxyacetyl nitrate, acrolein and formaldehyde, all strong oxidising agents, so the reason is true. These oxidants attack the carbon-carbon double bonds left in vulcanised rubber and break the chains, and the surface splits that follow are seen as cracking, so the assertion is true and the oxidising character named in the reason is what produces the cracking. Both the assertion and the reason are true, and the reason is the true explanation of the assertion.
JEE Main · 2021 · 26 Aug 2021 · Shift 2 · Single correct option